Device and method for measuring alternating injection-production damage of gas storage

Abstract

The invention provides a gas storage alternating injection-production damage measuring device and method, and belongs to the technical field of damage measuring devices.The gas storage alternating injection-production damage measuring device comprises a core holder and a high-pressure compressor, and a constant-flow constant-pressure pump, a preheater, a first back-pressure valve and a first sensor are sequentially connected between the high-pressure compressor and an inlet of the core holder through an inlet pipeline; and an outlet of the core holder is sequentially connected with a second sensor, a high-definition camera device and a sand collector through an outlet pipeline. Automatic data collection is achieved through the first sensor and the second sensor, meanwhile, the high-definition camera device can accurately record the sand production time and the sand production amount, and then the accuracy of data recording is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of damage measurement devices, and in particular relates to a device and method for measuring damage of alternating injection and production of a gas storage reservoir. Background Art

[0002] Gas storage facilities constructed from fully developed or commercially unavailable gas reservoirs are an effective solution for natural gas storage and peak load regulation. Depleted oil and gas reservoirs are a relatively common type of gas storage facility. Most of these reservoirs are constructed from loose and weakly consolidated sandstone, making them susceptible to rock damage and sand production under high-intensity alternating injection and production conditions.

[0003] During the operation cycle of a gas storage facility, the reservoir rock is subjected to cyclic loading and unloading, resulting in large alternating loads. The rock suffers fatigue damage under the alternating loads, and the fatigue of the reservoir rock reduces its strength, thereby increasing the risk of sand production. Many scholars have studied the rock damage caused by alternating injection and production. Zhang Peisen et al. conducted stress-seepage coupling experiments on sandstone under different confining pressures and cyclic loads to explore the various stages of rock failure under cyclic loads; Zhang Guangquan et al. studied the strength, permeability, and damage patterns of rocks under cyclic loads; Sui Yiyong et al. conducted experimental simulations of the sand production patterns of injection and production wells under alternating loads of strong injection and strong production, and studied the influence of rock damage and loading times on sand production in injection and production wells.

[0004] A relatively mature technology currently is the effect of long-term fluid migration on core pore structure damage and sand production (Patent Publication No.: CN214310067U). It relates to an experimental device for studying rock pore structure damage and sand production mechanisms, including a core, a core fixing device, and a drive device. The drive device includes a transmission rod, a displacement pump, and a control device respectively connected to the transmission rod. The transmission rod is connected to the displacement pump via a pipeline. The transmission rod is in turn connected to the control device via an electric motor and a cable. The transmission rod is provided with a water hole extending horizontally therethrough. The transmission rod includes a chassis fixed to the ground via a support frame. The chassis is provided with a hole in which the transmission mechanism of the electric motor is fixed. A cylindrical hole extending from top to bottom is provided in the center of the core, through which the transmission rod extends. The transmission rod, transmission mechanism, and upper core clamp are fixedly connected, and the transmission rod is movably connected to the lower core clamp. Drainage plates are vertically provided downwardly from the edges of both sides of the upper core clamp, and the lower core clamp is provided with a liquid outlet at a position corresponding to the drainage plate. A collection device is provided at the liquid outlet. However, the above technical solution cannot timely record data such as gas flow and pressure during the alternating injection and production process of the reservoir, and cannot timely record the sand production time.

[0005] Therefore, a measuring device is needed that can automatically record experimental data in real time and accurately. Summary of the Invention

[0006] In response to the above problems, the present invention proposes a gas storage alternating injection and production damage measurement device, including a core holder and a high-pressure compressor. A constant flow and constant pressure pump, a preheater, a first back pressure valve and a first sensor are connected in sequence between the inlet of the high-pressure compressor and the core holder through an inlet pipe; the outlet of the core holder is connected in sequence to a second sensor, a high-definition camera device and a sand collector through an outlet pipe.

[0007] Furthermore, the first sensor and the second sensor are both electrically connected to a data collector, and the data collector is electrically connected to the terminal.

[0008] Furthermore, the first sensor includes a temperature sensor and a first pressure sensor installed on the inlet pipe, and the first pressure sensor is located between the temperature sensor and the core holder.

[0009] Furthermore, the measuring device further comprises a safety valve, which is installed on the inlet pipe between the first back pressure valve and the temperature sensor.

[0010] Furthermore, the second sensor includes a second pressure sensor and a gas flow meter installed on the outlet pipe, and the second pressure sensor is installed between the gas flow meter and the core holder.

[0011] Furthermore, the measuring device also includes a back-pressure container and a second back-pressure valve connected in sequence, the first outlet of the second back-pressure valve is connected to a pressure gauge, and the second outlet of the second back-pressure valve is connected to a back-pressure pump; the inlet of the back-pressure container is connected to the second outlet of the first back-pressure valve, and the outlet of the back-pressure container is connected to the inlet of the second back-pressure valve.

[0012] Furthermore, a constant pressure pump is installed outside the core holder.

[0013] Furthermore, a temperature control device is installed on the outside of the core holder.

[0014] Furthermore, the outlet of the sand collector is sequentially connected to a pressure relief valve, a fourth back-pressure valve and an electronic balance.

[0015] A method for measuring alternating injection-production damage in a gas storage reservoir, using the above-mentioned device, comprises the following steps: Measure the amount of damage to the rock held in the core holder; Set the alternating cycle and number of times, and conduct core alternating displacement experiments; The first sensor and the second sensor collect data, and the high-definition camera device captures the sand-producing moment and takes photos for record; Upload the rock damage amount, data collected by the first sensor and the second sensor, and sand production photos collected by the high-definition camera to the terminal; The terminal analyzes the rock damage situation and records the critical sand production value through the rock damage amount, the data collected by the first sensor and the second sensor, and the sand production photos collected by the high-definition camera.

[0016] Furthermore, the alternating period is set to 1 minute or 2 minutes, and the alternating times are set to 30 times or 50 times.

[0017] Beneficial effects of the present invention: 1. The gas storage alternating injection-production damage measurement device of the present invention comprises a constant flow and constant pressure pump, a preheater, a first back-pressure valve, and a first sensor connected in sequence through an inlet pipe between the high-pressure compressor and the inlet of the core holder; a second sensor, a high-definition camera, and a sand collector are connected in sequence to the outlet of the core holder through an outlet pipe. The first and second sensors are used to automatically collect data, and the high-definition camera can accurately record the time and amount of sand production, thereby improving the accuracy of the recorded data.

[0018] 2. The present invention provides a first sensor and a second sensor, both of which are electrically connected to a data collector, which is electrically connected to a terminal, thereby achieving real-time measurement of flow, pressure, flow velocity and other related data of the gas storage reservoir, and calculating the damage of its core. When an abnormality occurs, it can promptly determine whether the gas storage reservoir will experience serious sand production, thereby eliminating monitoring delays.

[0019] 3. The gas storage alternating injection-production damage measurement device of the present invention can simulate rock alternating injection-production cycles and adjust itself based on varying gas storage conditions and environments (preheater temperature and high-pressure compressor pressure). This device measures reservoir damage based on actual alternating injection-production conditions and determines whether this damage will lead to increased sand production. This facilitates early detection and remediation of severe sand production issues, avoiding rock fatigue damage and increased sand production that can occur under long-term alternating injection-production conditions.

[0020] 4. The present invention implements automated and remote monitoring by providing a first sensor and a second sensor, eliminating the need for manual data collection and thus reducing human resources and operating costs. This method provides an innovative and efficient method for measuring damage from alternating injection and production in gas storage reservoirs. It aims to measure damage and predict critical sand production points, while also reducing costs and human resources requirements. It has broad application potential in the energy industry and related fields.

[0021] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic diagram of a gas storage alternating injection-production damage measurement device in Example 1 of the present invention is shown.

[0024] Figure 2 A schematic flow chart of a method for measuring alternating injection-production damage in a gas storage facility in Example 2 of the present invention is shown.

[0025] Figure 3 A schematic diagram of the thought process of the method for measuring alternating injection and production damage of a gas storage reservoir in Example 2 of the present invention is shown.

[0026] Figure 4 A schematic diagram of the change in confining pressure applied in Example 3 of the present invention is shown.

[0027] Figure 5 A schematic diagram of permeability change with an alternating time of 1 minute in Example 3 of the present invention is shown.

[0028] Figure 6 A schematic diagram of permeability change with an alternating time of 2 minutes in Example 3 of the present invention is shown.

[0029] Figure 7 A schematic diagram of the pressure difference change at both ends of the core in Example 3 of the present invention is shown.

[0030] Figure 8 A schematic diagram of permeability change in Example 3 of the present invention is shown.

[0031] In the figure, 11, high-pressure compressor; 12, constant-flow and constant-pressure pump; 13, preheater; 14, first back-pressure valve; 15, safety valve; 21, back-pressure container; 22, back-pressure pump; 23, pressure gauge; 24, second back-pressure valve; 31, core holder; 32, constant-pressure pump; 33, temperature control device; 41, temperature sensor; 42, first pressure sensor; 43, second pressure sensor; 44, gas flow meter; 51, high-definition camera; 52, sand collector; 53, decompression valve; 54, electronic balance; 55, third back-pressure valve; 56, fourth back-pressure valve; 57, data collector; 58, terminal. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1, refer to Figure 1 A device for measuring alternating injection and production damage in a gas storage reservoir includes a core holder 31 and a high-pressure compressor 11. A constant-flow and constant-pressure pump 12, a preheater 13, a first back-pressure valve 14, and a first sensor are sequentially connected via an inlet pipe between the inlet of the high-pressure compressor 11 and the core holder 31. A second sensor, a high-definition camera 51, and a sand collector 52 are sequentially connected via an outlet pipe to the outlet of the core holder 31. A temperature control device 33 is mounted on the core holder 31. Specifically, the high-pressure compressor 11 draws in and compresses air to provide the inlet pressure required for the experiment. The constant-flow and constant-pressure pump 12 controls the output gas pressure, which can reach up to 50 MPa. After exiting the high-pressure compressor 11, the gas is heated by the preheater 13 and then stabilized by the first back-pressure valve 14 (the device on the first back-pressure valve 14 (the back-pressure container 21, the second back-pressure valve 24, the pressure gauge 23, and the back-pressure pump 22) is used to apply back pressure). The injected gas can only enter the core holder 31 when the pressure exceeds the back-pressure value of the first back-pressure valve 14, supplying gas to the core holder 31 in a constant pressure mode. The constant-flow and constant-pressure pump 12 provides alternating pressure to the core holder 31 to simulate alternating injection and production conditions. The inlet pressure applied by the constant-flow and constant-pressure pump 12 at the core holder 31's inlet is manually adjusted according to experimental requirements. Alternating pressure is achieved by varying the pressure applied on both sides of the core at a fixed period.

[0034] Specifically, the high-definition camera device 51 includes a high-definition camera, which is placed at the sand outlet. At the moment of sand outlet, the sensor is triggered to automatically take pictures to obtain the critical sand outlet point.

[0035] Compared to existing methods, the present invention uses real-time sensor monitoring technology to simulate the alternating injection and production of gas storage facilities. This allows for timely recording of gas flow, pressure, and velocity during the alternating injection and production process. Based on this monitoring data and Darcy's law, the real-time permeability of the gas storage facility during the injection and production process is calculated. Furthermore, the damage to the rock within the reservoir is measured in conjunction with the actual alternating injection and production conditions of the gas storage facility. This, combined with actual field data, determines whether this situation will lead to increased sand production in the reservoir. This helps to identify and rectify serious sand production issues early, avoiding problems such as rock fatigue damage caused by long-term alternating injection and production cycles in gas storage facilities. This eliminates a significant amount of manual data collection, reducing manpower and operating costs. Furthermore, adjustments can be made based on changes in the conditions and environment of different gas storage facilities, providing more accurate prediction results.

[0036] In the implementation of the present invention, the first sensor and the second sensor are both electrically connected to a data collector 57, which is in turn electrically connected to a terminal 58. Specifically, the terminal 58 is a computer. The data collector 57 collects data from the temperature sensor 41, the first pressure sensor 42, the second pressure sensor 43, the gas flow meter 44, and sensors (such as the temperature sensor and pressure sensor) on the core holder 31, the high-definition camera 51, and other data, including the weight of gravel measured by the electronic balance 54, and transmits the data to the computer.

[0037] In the embodiment of the present invention, the first sensor includes a temperature sensor 41 and a first pressure sensor 42 installed on the inlet pipe. The first pressure sensor 42 is located between the temperature sensor 41 and the core holder 31. Specifically, the temperature sensor 41 is used to collect the inlet gas temperature, and the first pressure sensor 42 is used to collect the inlet gas pressure.

[0038] In the above embodiment, in another optional implementation, the measuring device further includes a safety valve 15, which is installed on the inlet pipe between the first back pressure valve 14 and the temperature sensor 41. Furthermore, the safety valve 15 is used to control the pressure of the gas entering the inlet of the core holder 31, thereby protecting the core holder 31.

[0039] Furthermore, the second sensor includes a second pressure sensor 43 and a gas flow meter 44 installed on the outlet pipe. The second pressure sensor 43 is installed between the gas flow meter 44 and the core holder 31. Specifically, the second pressure sensor 43 is used to measure the pressure of the gas at the outlet of the core holder 31, and the gas flow meter 44 is used to measure the flow rate at the outlet of the core holder 31.

[0040] In the embodiment of the present invention, the measuring device further includes a back-pressure container 21 and a second back-pressure valve 24, which are connected in sequence. The first outlet of the second back-pressure valve 24 is connected to a pressure gauge 23, and the second outlet of the second back-pressure valve 24 is connected to a back-pressure pump 22. The inlet of the back-pressure container 21 is connected to the second outlet of the first back-pressure valve 14, and the outlet of the back-pressure container 21 is connected to the inlet of the second back-pressure valve 24. Specifically, the back-pressure is applied by the operation of the back-pressure pump 22.

[0041] Furthermore, a constant pressure pump 32 and a temperature control device 33 are installed on the outside of the core holder 31. The constant pressure pump 32 is connected to the core holder 31. The constant pressure pump 32 is used to provide stable pressure to the core holder 31 to simulate formation pressure, and the temperature control device 33 is used to control the temperature of the core holder 31. The core holder 31 is a core fixing device. After the permeability of the experimental core is measured, it is placed in the core holder 31. The core is loaded with confining pressure to simulate the formation temperature and pressure, and the core is heated to the simulated formation temperature through the temperature control device 33. After the pressure difference between the two ends of the core is set, fluid is injected into the core holder 31 to conduct the experiment.

[0042] In this embodiment, the outlet of the sand collector 52 is sequentially connected to a pressure relief valve 53, a fourth back-pressure valve 56, and an electronic scale 54. The sand collector 52 collects the sand produced during the experiment, filters it, and then weighs it using the electronic scale 54 to determine the sand mass. Furthermore, a third back-pressure valve 55 is installed on the pipeline between the sand collector 52 and the high-definition camera 51.

[0043] Example 2, refer to Figure 2 A method for measuring alternating injection-production damage in a gas storage reservoir, using the apparatus described in Example 1, comprises the following steps: Measuring the amount of damage to the rock held in the core holder 31; Set the alternating cycle and number of times, and conduct core alternating displacement experiments; The first and second sensors collect data, and the high-definition camera 51 captures the sand production moment and takes photos for recording. Specifically, the sensors collect inlet pressure, outlet pressure, confining pressure (a pressure sensor is provided on the core holder 31), inlet temperature, formation temperature (a temperature sensor is provided on the core holder 31), and gas flow rate data, and transmit them to the terminal 58 for data processing. A change curve is generated for observing the core damage. Uploading the rock damage amount, the data collected by the first sensor and the second sensor, and the sand production photos captured by the high-definition camera 51 to the terminal 58; The terminal 58 analyzes the rock damage and records the critical sand production through the rock damage amount, data collected by the first sensor and the second sensor, and sand production photos captured by the high-definition camera 51.

[0044] Further, refer to Figure 3 The setting of the alternating cycle and number of times and the conducting of the core alternating displacement experiment include the following steps: Set the alternation period to 1 minute or 2 minutes, and the number of alternations to 30 or 50 times; The core holder 31 is subjected to alternating experiments by means of a constant flow and constant pressure pump 12 .

[0045] Example 3, The original formation pressure of the Shan 2 gas reservoir in a gas field is mostly between 24 MPa and 30 MPa, with an average of 27.2 MPa. The pressure coefficient is 0.94, which belongs to a normal pressure system. Therefore, a confining pressure of 27.2 MPa is used. The block core is placed in a core fixture and the following experiments are conducted: Experiment 1: The core was loaded with a stable inlet pressure (5 MPa) and a constant temperature gas (30°C). At this time, the pressure difference between the two ends of the core was stable at 5 MPa. During the experiment, the core was alternately subjected to a confining pressure of 15 / 40 MPa (see the variation of the applied confining pressure). Figure 4 ).

[0046] Under these experimental conditions, the core was subjected to confining pressure alternating experiments with alternating times of 1 minute and 2 minutes, and each condition was alternating 50 times. The pressure data was collected through the sensor, and the permeability was calculated once every 5 alternations. The specific permeability changes are as follows: Figure 5 As shown ( Figure 5 is the permeability with an alternating time of 1 min) and Figure 6 As shown ( Figure 6 is the permeability when the alternation time is 2 min).

[0047] Experiment 2: The core was loaded with confining pressure (27.2 MPa) and constant temperature gas (30°C). During the experiment, the inlet pressure was alternately applied at 8 / 21 MPa. During the experiment, the pressure difference between the two ends of the core was repeatedly changed between 8 MPa and 21 MPa (see the pressure difference between the two ends of the core for details). Figure 7 ).

[0048] Under this experimental condition, the core was subjected to an inlet pressure alternating experiment with an alternating time of 2 minutes 30 times, and the pressure data was collected by the sensor. Since the inlet pressure will change each time the alternating pressure changes, the permeability needs to be calculated for each change in the inlet pressure. The specific permeability changes are as follows: Figure 8 shown.

[0049] Based on the above experiments, the following conclusions can be drawn: ① During the alternating confining pressure experiment, the permeability of the core generally showed a downward trend. The permeability of the core varied at different cycles (alternating durations), and the damage caused to the core also varied.

[0050] ② During the inlet pressure alternation experiment, the core permeability did not change much after 30 alternations with an alternation period of 2 minutes; From the core data shown above, it can be seen that the permeability of the experimental core is relatively small, and it is impossible to determine whether sand production will occur during the experiment. In addition, sandstone has strong heterogeneity, and it is impossible to study the changes in the geological structure of the formation by studying the permeability differences of different cores under the same experimental conditions.

[0051] This project utilizes an experimental device to simulate the alternating injection and production process of a gas storage facility. By simulating rock alternating injection and production under different conditions, the changes in core permeability are compared. Sand production and permeability variations are used as two factors to determine rock damage. By observing these two factors, changes in the core can be determined. Under different experimental conditions, real-time changes in core permeability can be observed, and the impact of different factors on reservoir rock damage under alternating injection and production can be analyzed. During this experimental process, factors such as the experimental cycle and temperature can be adjusted according to actual operating conditions. This experiment can guide operations and identify the optimal injection and production cycle for the gas storage facility.

[0052] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0053] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

Claims

1. A gas storage alternating injection and production damage measurement device, characterized in that: The invention comprises a core holder (31) and a high-pressure compressor (11), wherein a constant flow and constant pressure pump (12), a preheater (13), a first back pressure valve (14), and a first sensor are sequentially connected between the inlets of the high-pressure compressor (11) and the core holder (31) via an inlet pipe; and a second sensor, a high-definition camera device (51), and a sand collector (52) are sequentially connected to the outlet of the core holder (31) via an outlet pipe.

2. A gas storage alternating injection-production damage measurement device according to claim 1, characterized in that: The first sensor and the second sensor are both electrically connected to a data collector (57), and the data collector (57) is electrically connected to a terminal (58).

3. A gas storage alternating injection-production damage measurement device according to claim 1 or 2, characterized in that: The first sensor comprises a temperature sensor (41) and a first pressure sensor (42) mounted on the inlet pipe, wherein the first pressure sensor (42) is located between the temperature sensor (41) and the core holder (31).

4. A gas storage alternating injection-production damage measurement device according to claim 3, characterized in that: The measuring device further comprises a safety valve (15), which is installed on the inlet pipe between the first back pressure valve (14) and the temperature sensor (41).

5. A gas storage alternating injection-production damage measurement device according to claim 1 or 2, characterized in that: The second sensor comprises a second pressure sensor (43) and a gas flow meter (44) installed on the outlet pipe, and the second pressure sensor (43) is installed between the gas flow meter (44) and the core holder (31).

6. The gas storage alternating injection-production damage measurement device according to claim 1, characterized in that: The measuring device further comprises a back-pressure container (21) and a second back-pressure valve (24) which are connected in sequence, wherein the first outlet of the second back-pressure valve (24) is connected to a pressure gauge (23), and the second outlet of the second back-pressure valve (24) is connected to a back-pressure pump (22); the inlet of the back-pressure container (21) is connected to the second outlet of the first back-pressure valve (14), and the outlet of the back-pressure container (21) is connected to the inlet of the second back-pressure valve (24).

7. The gas storage alternating injection-production damage measurement device according to claim 1, characterized in that: A constant pressure pump (32) is installed outside the core holder (31).

8. The gas storage alternating injection-production damage measurement device according to claim 1, characterized in that: A temperature control device (33) is installed outside the core holder (31).

9. The gas storage alternating injection-production damage measurement device according to claim 1, characterized in that: The outlet of the sand collector (52) is connected in sequence to a decompression valve (53), a fourth back-pressure valve (56) and an electronic balance (54).

10. A method for measuring damage caused by alternating injection and production of a gas storage facility, characterized in that: The device according to any one of claims 1 to 9 comprises the following steps: measuring the amount of damage to the rock held in the core holder (31); Set the alternating cycle and number of times, and conduct core alternating displacement experiments; The first sensor and the second sensor collect data, and the high-definition camera device (51) captures the moment of sand emergence and takes photos for recording; Sending the uploaded rock damage amount, the data collected by the first sensor and the second sensor, and the sand production photos collected by the high-definition camera device (51) to the terminal (58); The terminal (58) analyzes the rock damage situation and records the critical sand production value through the rock damage amount, the data collected by the first sensor and the second sensor, and the sand production photos collected by the high-definition camera (51).

11. A method for measuring damage caused by alternating injection and production of a gas storage facility according to claim 10, characterized in that: The alternating period is set to 1 minute or 2 minutes, and the alternating times are set to 30 times or 50 times.

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